Geothermal energy is an abundant green energy from the Earth and has potential for development. However, due to its unique components, a change of temperature or pressure may easily cause geothermal fluids to form scales on the wellbore walls or in the formation fractures, which increases the instability of geothermal fluid production.
An acid or chemical treatment has been internationally used against geothermal scale formation. However, the waste fluids left from the acid or chemical treatment cause severe environmental pollution.
On the other side, precious metals are not rich in industrial wastewater, geothermal fluids or hot springs. Therefore, to extract precious metals from these liquids by using physical or chemical methods is not efficient and the extraction may cause environmental pollution as mentioned above.
Thus, development of green energy with high production efficiency, while being environmentally friendly, is being researched more and more.